Hello,
If what you said is correct, if it is really related to gas. It can be definitely be cured in Homeopathy taking all of his symptoms into consideration. Swelling, especially on the right side is a thing to be concerned but if it is general flatulent distension, it can be cured. You can ask your friend to consult any experienced homeopath with required tests to get completely cured.
Next Steps
The patient needs to undergo certain simple yet important diagnostic tests (for getting an even clearer picture) like -
1. Complete Blood Picture.
2. Complete Urine Examination.
3. Ultrasound scan of the Abdomen.
Health Tips
Try to avoid :
1. Pressure over the affected area.
2. Forward bending.
3. Oily or fried foods.